The field of this disclosure relates generally to air handling systems, and more specifically, to directing airflow in heating, ventilating, and air conditioning (HVAC) systems that include the use of vortex generators.
Some known HVAC systems utilize centrifugal fans or other air handling apparatus to circulate air through ductwork systems and deliver conditioned air to a space. To circulate air, centrifugal fans in HVAC systems push large amounts of air through the fan housing and into attached ductwork systems. The centrifugal fans may generate unfavorable flow structures, such as, for example, large swirling vortexes of air. Additionally, unfavorable flow structures can be generated wherever the air is redirected, such as at turns in the ductwork system or at vanes. The unfavorable flow structures generate noise and decrease the efficiency of HVAC systems. Therefore, a means to break up or prevent these unfavorable flow structures would decrease the sound and increase the efficiency of HVAC systems. As HVAC systems are often used in occupied spaces, the noise generated by an HVAC system can disturb the occupants of the conditioned space.
Systems for lessening the noise generated by HVAC systems are known in the art. In one such system, an acoustic wave modulator configured to reduce turbulence of the air is placed in a duct assembly adjacent a fan. The acoustic wave modulator has one or more fins attached to a cylindrical structure. The cylindrical structure acts as a hub and has an axis generally parallel with the direction of airflow. The acoustic wave modulator attempts to straighten the airflow, i.e., force the air to flow in only one direction, directly adjacent the fan. The acoustic wave modulator does not reduce all sound and is designed for use only adjacent the fan.
Alternatively, sound in HVAC systems can be reduced by placing active sound controls and/or filter media in the duct systems. However, the acoustic filter media and active sound controls can decrease efficiency of the HVAC system.